I may not be fortunate enough to own a big tech company myself, but if I did? NYC would probably be one of the LAST places on my list where I'd consider an expansion or a move.
Real estate is insane, obviously ... but you're also dealing with the transportation headaches. Where I work now, we already have some big problems with that, and we don't have NYC's density. (Everyone's pushed and prodded to use public transportation since cars are impractical with high daily parking costs, traffic jams, etc.) But with public transportation, you're really limited in what you can carry. Any kind of office outing requires renting an expensive bus to shuttle everyone to or from the event, too. And if the subway has a problem, you may as well shut the place down until they get things fixed. Additionally, your employees who might otherwise be happy to work late or odd hours to finish some project are constrained by the hours the bus or metro runs. So you lose some potential productivity there too.
You pretty obviously don't live in NYC...
Transit runs 24 hours a day 365 days a year, any time they do maintenance there are alternatives routes, if there's no nearby train they will set up shuttle service, and there's an extensive bus network too. Beyond that, the infrastructure for taxis and cars for hire is better than anywhere in the world that I've been. This place does NOT shut down due to transit issues. Even after Sandy came by and completely flooded a bunch of tunnels, service got restored quickly to all the other lines. There was no power in lover Manhattan for weeks, but I could still take the train to work in Queens without problems.
You also have to figure that in many ways, the tech market there is saturated. It's not like all the Wall Street traders don't have any contacts to work with to provide their network bandwidth or computer maintenance. If you move out to NYC, it sounds to me like a tough, uphill battle if you want to establish yourself as a contender?
I'd say that's true anywhere. NYC is pretty unforgiving of mediocrity, so I imagine you'll go out of business faster here if your company sucks, but if you start a sucky business elsewhere it'd just be postponing the inevitable. And who knows? Your sucky business might be made more awesome by the talent pool here and the massive amount of potential clients within walking distance. Sure, maybe Wall Street isn't going to be the place to go if you're a network provider, but pretty much every other business in the city is fair game, and there are A LOT.
If the physical presence makes no difference (software development, for example) -- then you want the CHEAPEST place you can build an office and still be able to hire good talent. I think what many companies would find if they actually thought "outside the box" a bit, is that there's a LOT of great computer talent in the small, rural communities. Kids growing up there don't have as much to do, so many gravitate towards the home computer and the internet, and spend a lot of time with it. The technical minded who don't envision themselves working the family farm like their parents did constitute a good hiring pool that's neglected.
If that's your company's deal, go for it. NYC is filled with young motivated talented charismatic individuals fueled on dreams and starbucks, all fighting to make their mark. Rural communities, from the way you describe them, have a few talented people that would really like to get out of their rural communities... Probably wishing to move to a place like NYC.